Monday, January 23, 2012

HERE ARE SOME RECENT PHOTO-EVIDENCE OF FOLIAGE DEMISE IN SANTA BARBARA, CA 93101. I TAKE NO PLEASURE IN POSTING THESE BUT AIR POLLUTION IS KILLING OUIR PLANT LIFE. CHLOROPHYLL AND PHOTOSYNTHESIS HAS BEEN BURIED BY BLACK POWDERED TRAFFIC DUST.

1 comment:

Ha, I'm going crazy trying to get a real webpage up. I'm no good at this stuff. But, meanwhile I did type in portions of a book that includes the history of air pollution - with the citrus photos, I think you'll appreciate it:

It is at this time that the first records appear to have been made of damage to vegetation. In 1661, the English diarist, John Evelyn, published his famous treatise, Fumifugium: Or the Inconvenience of the Aer and Smoake of London Dissipated, in which he described the contemporary air pollution problems in teh English capital, making recommendations for their amelioration.

Fumifugium contains graphic descriptions of effects on vegetation, such as '...Our Anemonies and many other choycest Flowers, will by no Industry be made to blow in London or the Precincts of it, unless they be raised on a Hot-bed and governed with extraordinary Artifice to accelerate their springing; imparting a bitter and ungrateful Tast to those few wretched Fruits, which never arriving to their desired maturity, seem, like the Apples of Sodome, to fall even to dust, when they are but touched.'

Fascinatingly, Evenlyn also describes what can be described as the first experiment, albeit inadvertant, on air pollution impacts on plants, when coal smoke was eliminated in London one summer as a result of the English Civil War stopping the coastal trade concerned, with him noting how the trees produced uprecedented quatities of high quality fruit. Clearly air quality deteriorated even further over the net 100 years, as a preface to a second ediition of Fumifugium, written in 1772 noted 'It would now puzzle the most skilful gardener to keep fruit trees alive in these places: the complaint at this time would be, not that the trees were without fruit, but that they would not bear even leaves.'

During the 1960's, ozone injury became widely recognised throughout the USA on numerous crops and forests. Agricultural areas of Canada were also impacted. By 1970, ozone concentrations were found to be elevated in Europe and injury reported on indictor plants and forest species.

Subsequently O3 was demonstrated to be the most important phytotoxic pollutant in Europe as well as in North America, with studies using filtered chambers or chemical protectants demonstrating growth reductions and/or visible injury in many locations. Over the same period it also became apparent that there were major oxidant problems in Japan, but it took much longer to recognise that this presented a significant environmental issue in the developing world. This is unfortunate, because growing emissions of precursors and meteorological conditions favourable to its formation are both prevalent in many developing countries. Yet, there is little O3 measurement carried out in such places, and even this is normally confined to the cities. However, evidence is now accruing, either on a predicted basis or by experimental demonstration that there may be major O3 effects on crop growth in China, Egypt, India and Pakistan.